• Journal of the Korean Ceramic Society
• /
• v.32 no.12
• /
• pp.1383-1391
• /
• 1995

Hexagonal $\delta$-FeOOH was coated with Ba-Sol, which was produced by hydrolizing Ba(OC2H5)2, Ba-Sol coated $\delta$-FeOOH spread on a stainless plate, dried at 8$0^{\circ}C$ and then heat-treated. In this way, Ba-ferrite fine particles were produced. although there was a difference in a degree of hydrolysis of Ba(OC2H5)2, crystalline phase of Ba-ferrite appeared around 617$^{\circ}C$, and Ba-ferrite single phase was obtained after heat treatment at 80$0^{\circ}C$ for 2 hr. When Ba-ferrite was made from Ba-Sol coated $\delta$-FeOOH, $\delta$-FeOOH was thermally decomposed to $\alpha$-Fe2O3 at $700^{\circ}C$, producing a porous structure which was observed by TEM photographs. But the porous structure was not observed at 80$0^{\circ}C$. Ba-ferrite, heat-treated at 80$0^{\circ}C$ for 2 hr, had mean particle size of 1000$\AA$, lattice parameter of a0=5.889243 $\AA$ and c0=23.214502 $\AA$, a saturation magnetization ($\sigma$8) of 45.3 emu/g and a coercive force (Hc) of 5200Oe.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.1030-1035
• /
• 2001

Strontium barium niobate, (Sr$\sub$0.5/Ba$\sub$0.5/Nb$_2$O$\sub$6/), thin films of various composition were prepared by the sol-gel method. Solution derived from acetate powders and niobium ethoxide in a mixture of acetic acid, ethylene glycol and 2-methoxyehanol was spin-coated onto bare silicon, Pt-coated silicon and fused silica substrates. Processing parameters were optimized to develop stable solutions which yielded films with relatively low crystallization temperatures. It was determined that ethylene glycol was a necessary component of the solution to increase stability against precipitation and to decrease the crystallization temperature of the films as confirmed by XRD and FT-IR analyses.